Tell yourself you’re not tired.

Dwelling on how exhausted you are may only make you feel more run down, according to a new study in the Journal of Experimental Psychology. Researchers asked 164 participants how they’d slept the previous night, then hooked them up to a sham machine that purportedly revealed to scientists their REM sleep. People who were told they had above-average REM sleep performed better on cognitive and attention tasks than those who were told their REM sleep was below average, regardless of how they’d actually slept.

Don't hit snooze.

"The worst mistake I see my sleep-deprived insomnia patients make is staying in bed in the morning to try to reach the magic eight hours," Chad Ruoff, MD, a clinical assistant professor of psychiatry at the Stanford University Sleep Center, told HuffingtonPost.com. This throws your body off schedule, which can make it harder to fall asleep the next night.

Ignore your cravings.

“As tempting as it may be to reach for a bacon, egg, and cheese sandwich or a chocolate-chip muffin, giving in to cravings can backfire,” notes FitnessMagazine.com. “Fatty foods require a lot of energy to digest, leaving you even more sluggish, and sweet treats and processed carbohydrates cause your blood sugar and energy levels to spike and crash.” Try a mix of complex carbs and protein, like oatmeal with fruit.

Alternate physical and mental activity.

Slog away at your desk for an hour, then take a break to walk or stretch. Watch a TV show on the couch, then head out to pick up the mail. This toggling back and forth between rest and activity usually improves alertness, according to Matthew Edlund, MD, on PsychologyToday.com.

Drink your caffeine in the AM.

"Caffeine is definitely beneficial for keeping individuals who are sleep deprived more alert," Timothy Roehrs of the Sleep Disorders and Research Center at Henry Ford Hospital in Detroit told the Nutrition Action Health Letter. The stimulant temporarily binds to your brain’s receptors for a chemical called adenosine, which is a natural sedative, the newsletter explains. By blocking out adenosine, caffeine makes you feel more alert. Yet after a night of little sleep, regular caffeine drinkers may need more than their normal intake for a significant energy boost.

Get outside.

Exercise—even a slow walk—may be the last thing on your mind when you're fried from fatigue, but "movement stimulates alertness in the brain, and sunlight provides your body with natural cues to promote wakefulness," Jeffrey Durmer, MD, chief medical officer at FusionSleep Center in Atlanta, told WebMD.com. Specifically, sunlight turns off the production of melatonin, the hormone that triggers feelings of sleepiness.

Power nap if you're driving.

If you're tired, you may be more impaired behind the wheel than you realize. According to the National Highway Traffic Safety Administration, drowsy driving causes more than 100,000 crashes a year—resulting in 40,000 injuries and 1,550 deaths—and that number is likely underreported. If you must get behind the wheel, power nap first, NYU sleep disorders expert Joyce Walsleben, PhD, told WebMD.com. Be especially cautious if you drive in the early afternoon. "Most people naturally drift around 1 or 2 p.m., and those who are sleep deprived will take a bigger hit," she told the site.

Avoid intense workouts.

It’s true that regular exercisers tend to sleep better than less active folks. But if you’re tempted to hit the gym the day after you’ve been up all night, you might increase your risk of injury, according to FitnessMagazine.com. "When you're feeling sleepy, back off a little from your workout status quo; reduce the intensity and duration of your exercise," Shawn Youngstedt, PhD, an associate professor of exercise science at the University of South Carolina in Columbia, told the site.